Blame view

kernel/linux-rt-4.4.41/drivers/media/usb/gspca/sn9c2028.h 1.78 KB
5113f6f70   김현기   kernel add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
  /*
   * SN9C2028 common functions
   *
   * Copyright (C) 2009 Theodore Kilgore <kilgota@auburn,edu>
   *
   * Based closely upon the file gspca/pac_common.h
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   */
  
  static const unsigned char sn9c2028_sof_marker[] = {
  	0xff, 0xff, 0x00, 0xc4, 0xc4, 0x96,
  	0x00,
  	0x00, /* seq */
  	0x00,
  	0x00,
  	0x00, /* avg luminance lower 8 bit */
  	0x00, /* avg luminance higher 8 bit */
  };
  
  static unsigned char *sn9c2028_find_sof(struct gspca_dev *gspca_dev,
  					unsigned char *m, int len)
  {
  	struct sd *sd = (struct sd *) gspca_dev;
  	int i;
  
  	/* Search for the SOF marker (fixed part) in the header */
  	for (i = 0; i < len; i++) {
  		if ((m[i] == sn9c2028_sof_marker[sd->sof_read]) ||
  		    (sd->sof_read > 5)) {
  			sd->sof_read++;
  			if (sd->sof_read == 11)
  				sd->avg_lum_l = m[i];
  			if (sd->sof_read == 12)
  				sd->avg_lum = (m[i] << 8) + sd->avg_lum_l;
  			if (sd->sof_read == sizeof(sn9c2028_sof_marker)) {
  				PDEBUG(D_FRAM,
  					"SOF found, bytes to analyze: %u."
  					" Frame starts at byte #%u",
  					len, i + 1);
  				sd->sof_read = 0;
  				return m + i + 1;
  			}
  		} else {
  			sd->sof_read = 0;
  		}
  	}
  
  	return NULL;
  }